Patent GB-898424-A (GB)
Title: Improvements in or relating to flight training or simulating apparatus
Inventor: MARVIN RONALD ARTHUR
IPC: G09B9/20
Filed: 1960-11-23
Abstract: 898,424. Grounded flight trainers. COMMUNICATIONS PATENTS Ltd. Nov. 23, 1960 No. 40295/60. Class 4. Auxiliary apparatus for an electronic flight trainer or simulator comprises computing means, separate from the computing means of the flight trainer or simulator from which signal outputs are derived for feeding to electronic computer means forming a part of said flight trainer or simulator, and means for providing adjustably variable electrical inputs to the separate computing means of the said auxiliary apparatus, whereby simulated conditions of aircraft attitude, altitude and air speed can be maintained in the trainer or simulator during a prolonged period .of time, without the use of flying controls forming a part of the said flight trainer or simulator. The apparatus comprises. a slector box 10, provided with controls to enable values of pitch and roll .to be set up manually so that required conditions of altitude, attitude and airspeed can be established in the simulator, and three computing units 15, 16 17 permanently installed in the computing section of the simulator, the selector box and computing units being joined together by a multi-way plug and socket connector 18. Box 10 includes a roll control 11, coarse and fine pitch controls 12 and 13 respectively, and a two-position altitude lock/speed lock switch 14, all controls being manually adjustable. Roll control 11 is a potentiometer having a winding 20 centre tapped at 23 and supplied with D.C. current from a source 77, the positive and negative poles of which are connected to terminals 24 and 25 of block 18. From the wiper a signal is passed over line 26 to an input terminal 27 of computing unit 15, the signal corresponding to the magnitude and direction of roll angle set in by control 11. The computing unit 15 comprises a D.C. amplifier 35 and a summing network of three resistors 30, 31 and 32 connected respectively to input terminals 27, 28 and 29 the signals applied thereto respectively consisting of command, monitoring and stabilising feed-back signals. Amplifier feedback is provided by resistor 33 and a capacitor 34. The command signal is answered by the monitoring signal which is proportioned to Cos # sine ° and is obtained from computing elements 36 and 36<SP>1</SP> forming part of the computer of the simulator # is pitch angle and ° roll angle). The rate of roll stabilizing signal at terminal 29 is obtained from a computing element 37 also forming part of the simulator computor. The output of unit 15 is used as a rolling moment signal and is fed over lines 38 and 42 to an input terminal 43 of a roll angle computing system forming part of the simulator where it is summed with any rolling moment signal present if the aileron control is not at neutral setting. In an actual aircraft the rudder is used to inhibit sideslip and comput-, ing unit 17 is used to provide a moment signal in the jaw angle computing system of the simulator which will satisfy this condition, but no command signal input is supplied to the computing unit 17 from selector box 10. Unit 17 comprises a D.C. amplifier 44 and a summing network of .three resistors 45, 46 and 47 connected respectively to input terminals 48, 49 and 50, the signals applied to terminal 49 corresponding to rate of yaw obtained from a computing element 54 associated with the yaw angle computing system and the inputs to terminals 48 and 50 being obtained respectively from computing elements 53 and 55 of a sideslip angle computing system in the simulator. The yawing moment output signal from unit 17 is fed via lines 56 and 60 to input terminal 61 of the yaw computing system of the simulator where it is summed with any signal input derived from the simulated rudder controls. The switch 14 in box 10 enables either constant altitude or constant airspeed conditions to be maintained in the simulator by providing two different pairs of inputs to computing unit 16. This comprises a D.C. amplifier 62 and a summing network of three resistors 63, 64 and 65 and a capacitor 66 connected respectively to input terminals 67, 68, 69 and 70, amplifier feedback being provided by a resistor 71 and capacitor 72. A command signal fed to terminal 67 over line 84 and wiper 82 of a potentiometer 81 forming the fine pitch control unit 13, the potentiometer being energized from the coarse pitch control unit 12 which comprises two ganged five position switches 73 and 74 to provide five different voltage ranges to control 13. The input signal at 67 is answered by a monitoring signal derived from a height computing element 95 in the simulator and fed to terminal 68 over line 94 from the box 10 as a signal proportional to altitude. With switch 14 adjusted from terminal 85<SP>1</SP> to 85<SP>11</SP> the input at 68 is .derived from an airspeed computing element 97 in the simulator as a signal proportioned to airspeed. The input signal to terminal 69 corresponds either to longitudinal acceleration or rate of climb according to whether it is connected to elements 98 or 96 in the simulator. A further stabilising signal is fed to terminal 70 from a computing element 78 of the pitch system of the simulator, this input being differentiated by capacitor 66 to form a signal proportional to rate of change of the sine of the pitch angle. The output of unit 16 is fed via lines 100 and 104 to terminal 105 of the pitch computing system of the simulator.